Recipes

How to measure to exercise intensity

To get the most from your workouts you need to learn how to gauge how hard you’re exercising, i.e. exercise intensity. If you’re going to work out, you want to know you’re getting the best results that you can for the effort, time and sweat you’re putting into it.

So what’s exercise intensity? Exercise intensity is related to how hard an activity feels to you. More specifically exercise intensity is determined by heart rate, but also by how hard you’re breathing, whether you’re sweating, and how tired your muscles feel.

There are a quite few ways in which you can measure or guesstimate exercise intensity, and most of them are pretty simple. Just pick the one that works for you.

1. BREATHING PATTERN

When you perform aerobic exercise such as jogging or rowing, your muscles use more oxygen and produce carbon dioxide. Carbon dioxide levels are monitored by chemoreceptors in your blood vessels which send messages to your lungs via your brain to increase the speed and depth of your breathing.

As you increase the intensity of your workout, you switch from nose breathing to mouth breathing. This is (or was because now you’ll be looking for it!) an automatic response to the increased demand for oxygen and occurs at around 60% of your maximum heart rate. Bottom line – if you are breathing through your nose when doing your cardio, you’re probably in your recovery training zone.

2. APPEARANCE

Like a bad gambler, you have an exercise “tell”. You may go red, sweat at a certain exercise intensity, develop an intense “thousand yard stare”, clench your fists or a host of other signs that happen when you hit your training sweet spot. Once you know what your “tells” are, you can use them to monitor the intensity of your workout. This method, like breathing above, is a subconscious indicator of how you are feeling. But now, because you are aware of it, you need to relax and just “let it happen”.

3. TALK TEST

Talking is reliant on your ability to breathe — specifically exhale. When you exercise your breathing rate increases as your need for oxygen increases. The faster your breathing rate, the harder it is to talk. Next time you are working out, try chatting to a friend and monitor your speech patterns. If you can tell them where you are going for your holiday, what you are going to pack, the time of your flight, who you are traveling with, what you are hoping to see and the color of your swimsuit without pausing for breath you probably aren’t working hard enough! If, however, you are reduced to monosyllabic words and grunts, you are probably working too hard…certainly beyond your aerobic training zone.

One or two breaths per sentence would suggest that you are working aerobically and will get plenty of benefit from your workout.

4. HEART RATE

Heart rate is a great way to determine exercise intensity, because it’s not subjective. Your heart drives blood around your body. The harder you exercise, the greater the demand for oxygenated blood, and therefore the higher your heart rate will be. Because your heart responds to exercise in a very predictable way, you can use your heart rate to monitor exercise intensity. You can measure your heart rate by using a heart rate monitor, taking your pulse at your wrist or neck, or using the sensors built in to cardio exercise equipment.

5. RATING OF PERCEIVED EXERTION (RPE)

Attributed to Swede Gunner Borg, the rating of perceived exertion scale, or RPE for short, is a method of monitoring intensity based on how you feel while exercising. Borg’s original scale runs from 6 to 20 which may seem a little odd but Borg was working with very fit athletes who, on average, had a resting heart rate of around 60 bpm and a maximum heart rate of 200 bpm. By “knocking off” a zero, he devised a scale that was linked to heart rate but didn’t actually require his athletes to monitor their pulses. Instead of working at, for example 140 bpm, Borg would have his athletes exercise at level fourteen.

With practice, using Borg’s scale can be very precise but some users find the concept of a 6-20 scale off putting and, as a result, a modified version of Borg’s scale emerged. Many users find this modified 1-10 scale far more logical and user friendly.

The main disadvantage with perceived exertion is that it doesn’t take into account exercise discomfort tolerance. If you find a particular activity uncomfortable, you will probably perceive that you are working harder than you actually are.

To get this scale clear in your mind, imagine level one is equal to being sat at home, feet up, watching TV whilst level ten is sprinting after a bus that just won’t stop. By combining the talk test, observing breathing patterns and using RPE, you should be able to accurately estimate how hard you are working and get yourself into the appropriate heart rate training zone without having to use a heart rate monitor.